Age inline caches after context disposal.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index c7093a817bfc46bb939701f7a63497de22a1261d..675c2da57e1df433b48bfecb3f380cf31a4b9fa1 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -4174,6 +4174,11 @@ class Code: public HeapObject {
   // it is only used by the garbage collector itself.
   DECL_ACCESSORS(gc_metadata, Object)
 
+  // [context_disposed_count]: The value of the global_context_disposed_count
+  // at the moment when this code object was created.
+  inline void set_context_disposed_count(int count);
+  inline int context_disposed_count();
+
   // Unchecked accessors to be used during GC.
   inline ByteArray* unchecked_relocation_info();
   inline FixedArray* unchecked_deoptimization_data();
@@ -4426,8 +4431,9 @@ class Code: public HeapObject {
   static const int kTypeFeedbackInfoOffset =
       kDeoptimizationDataOffset + kPointerSize;
   static const int kGCMetadataOffset = kTypeFeedbackInfoOffset + kPointerSize;
-  static const int kFlagsOffset = kGCMetadataOffset + kPointerSize;
-
+  static const int kContextDisposedCountOffset =
+      kGCMetadataOffset + kPointerSize;
+  static const int kFlagsOffset = kContextDisposedCountOffset + kIntSize;

[Vyacheslav Egorov (Chromium), 2012/03/22 14:47:05]

I wonder how big our Code object will become with an addition of this one field.

I think it will grow by 50% because of the alignment. 

   static const int kKindSpecificFlagsOffset = kFlagsOffset + kIntSize;
   static const int kKindSpecificFlagsSize = 2 * kIntSize;
 
@@ -5322,6 +5328,11 @@ class SharedFunctionInfo: public HeapObject {
   inline int ast_node_count();
   inline void set_ast_node_count(int count);
 
+  // The value of the global_context_disposed_count at the moment
+  // when the opt_count was reset.
+  inline int context_disposed_count();
+  inline void set_context_disposed_count(int count);
+
   // Add information on assignments of the form this.x = ...;
   void SetThisPropertyAssignmentsInfo(
       bool has_only_simple_this_property_assignments,
@@ -5496,8 +5507,10 @@ class SharedFunctionInfo: public HeapObject {
       kInferredNameOffset + kPointerSize;
   static const int kThisPropertyAssignmentsOffset =
       kInitialMapOffset + kPointerSize;
-  static const int kProfilerTicksOffset =
+  static const int kContextDisposedCountOffset =
       kThisPropertyAssignmentsOffset + kPointerSize;
+  static const int kProfilerTicksOffset =
+      kContextDisposedCountOffset + kPointerSize;
 #if V8_HOST_ARCH_32_BIT
   // Smi fields.
   static const int kLengthOffset =